1. Field of the Invention
This invention relates to a control valve device to control the movement of at least one hydraulic user. Specifically, in the present invention, as a result of a relative movement of a control spool valve of a control valve with respect to a housing, the connection of at least one hydraulic connection that is in communication with the user with a delivery connection and with a reservoir connection can be controlled, the control spool valve can be moved relative to the housing by an actuator device, and the housing has a multi-layer construction consisting of plates that are connected to one another by an adhesive or an additional substance, which plates comprise intermediate plates that are located between two end plates.
2. Background Information
Control valve devices that control the flow of hydraulic fluid to and from a user can be control valves for the actuation of a single-action user, for example a lifting cylinder of an industrial truck, and control valves for the actuation of a double-action user, for example a tilting cylinder of an industrial truck. The actuation devices of the control spool valve can be mechanical, hydraulic, pneumatic or electrical actuation devices.
The housing of the control valve device of the present invention has a multi-layer construction of a plurality of plate-shaped sheets connected to one another by an adhesive or an additional substance, in particular by soldering, e.g., hard soldering or brazing. This construction significantly reduces the size and weight of the housing compared to cast housings.
A control valve device of the prior art with a housing that is soldered together from a plurality of plate-shaped sheets for the actuation of the work hydraulic system of an industrial truck is described in DE 197 16 442 A1. In this prior art control valve device, inside the housing there are corresponding recesses in the sheets to create a pump channel, a reservoir channel and corresponding hydraulic channels that lead to the users. For the connection of the pump channel to the delivery line of the pump, for the connection of the reservoir channel to a recirculation line and for the connection to the hydraulic channels of the hydraulic lines leading to the users, there are separate connection sockets or housing parts that must be connected with the housing. The actuator device can be a stepper motor or a proportional magnet, for example, a separate housing part which must be connected with the housing is necessary for the fastening of the actuator device of the control valves. The connection sockets of the delivery line and of the reservoir line are thereby soldered into the pump channel or the reservoir channel of the housing. If the independent housing parts are bolted to the housing, special thread inserts are required, which must be soldered into corresponding borings in the housing that are formed from recesses in a plurality of plates. The result, however, is a difficult, time-consuming and expensive manufacturing process, because the connection sockets and the thread inserts must be manufactured separately and must then be soldered into the housing in corresponding borings formed from recesses in a plurality of plates. In addition, a large number of parts are required as well as a correspondingly high amount of labor for the assembly of the plates and of the connection sockets and thread inserts for the soldering process.
The object of the invention is to make available a control valve device that can be constructed easily and quickly and is economical to manufacture.
The invention provides that the thickness of the end plates exceeds the thickness of the intermediate plates. The end plates are provided with a fastening device for the actuator device and/or one or more connection devices for the delivery line that is connected with the delivery connection, for the reservoir line that is connected with the reservoir connection, and/or for the hydraulic line that is connected with the hydraulic connection.
The end plates of the housing are thicker than the intermediate plates. Therefore, the connection devices required for the connection of the hydraulic line, the reservoir line and the delivery line can be provided on the end plates, as can the fastening device for the fastening of the actuator device. This arrangement results in a series of advantages.
Providing all the necessary connection devices for the corresponding lines and fastening devices for the actuator devices of the control valve device eliminates additional connection sockets and thread inserts that would have to be soldered in corresponding recesses in a plurality of plates of the housing. Therefore, the cost and time required for manufacture is reduced, as is the number of parts required, which reduces the time and cost of assembly. In addition, the thick end plates increase the rigidity of the housing. Pressurized channels can now be located in the outer portion of the housing. The thick end plates, as a result of their weight, act as weighting plates during the soldering process. During soldering joints between the plates are oriented in a horizontal plane. As a result, the plates are pressed together during the soldering with a defined force, and there are defined, uniformly thick layers of solder between the plates. This construction eliminates the use of fixing devices, e.g., separate weighting plates, or riveted fixing bars connected to the end plates, which were previously necessary in the soldering process on valve devices with a housing that consists of uniformly thick plates. This further reduces the time and cost of manufacturing and assembly.
In one configuration of the invention, the fastening device for the actuator device and/or the connection devices, for the delivery line, the reservoir line, and/or for the hydraulic line are each at least one threaded boring located in an end plate. With a threaded boring located in an end plate, it becomes possible to easily fasten or connect the actuator device, the delivery line, the reservoir line and the hydraulic line to the housing. In addition, the threaded borings can be introduced into the end plates before the soldering process. Consequently, the manufacture of the housing of the control valve device can be simplified.
In one embodiment, in which the control spool valve is located in a housing boring that is formed from recesses in the intermediate plates and in the end plates, little time or effort is required for the fastening of the actuator device if the threaded boring is located in a flange area of the actuator device that surrounds the recess in an end plate.
Some of the intermediate plates and at least one end plate are provided with recesses that are in communication with one another. As a result of the contour and the arrangement of the recesses with respect to one another, a pump channel, a reservoir channel and at least one hydraulic channel are formed. The delivery line, the reservoir line and the hydraulic line can be quickly and easily connected to the end plate and thus to the housing if the recesses located in the end plate are realized in the form of threaded borings. The recess thus forms a part of the corresponding hydraulic channel, whereby the corresponding line can be screwed into the threaded boring in the recess.
In one refinement of the invention, at least one end plate includes at least one fastening device for the fastening of the control valve device to a control valve support. The fastening device for fastening the control valve device to a valve support, such as a vehicle body, for example, is thereby located on the end plates, reducing time and effort required for manufacture and assembly. The fastening device can be located on the lateral surface of the end plate providing good accessibility for the fastening device. In addition, no additional space is occupied by the fastening device on the end surfaces of the end plates, on which the actuator devices and the connections of the lines are located.
A smaller number of parts and thus reduced time and cost of manufacture and assembly for the control valve device can be achieved if the device is shaped onto the end plate. The housing boring of the control spool valve may be closed on the side opposite the actuator element with a housing cover, whereby the end plate opposite the actuator device is provided with a fastening device for the housing cover. The fastening device of the housing cover is thereby provided on the corresponding end plate, whereby the housing boring can be closed in a simple manner.
The time and effort required for manufacture and assembly can be reduced if the fastening device for the housing cover is at least one threaded boring that is located in the end plate. For this purpose, the one part of the recess in the end plate that forms the housing boring can be a threaded boring, and the housing cover can be a screw plug. Alternatively, the housing cover can have a flange, whereby corresponding threaded borings can be provided in the end plate in the flange area of the housing cover.
In one embodiment of the invention, in which there is at least one additional hydraulic component, which is located in a concentrically located recess of some of the intermediate plates and at least one end plate, the time and effort required for manufacturing and assembly can be reduced if a fastening device is provided for the additional component on the end plate. The additional component can be, for example, a check valve for the leak-free isolation of the user, a neutral circulation valve, a pressure relief valve or a delivery flow sensor to detect the speed of movement of the user. The recess that is necessary for the installation of the component can be quickly and easily closed, or a pilot device of the component can be fastened to the end plate by a fastening device that is located on the end plate.
The recess in the end plate may be a threaded boring. In this case, the housing boring, for example of a check valve, can be easily and quickly closed by a screw plug. The fastening device can also be at least one threaded boring that is located in the flange area of the component in the end plate. The actuation device of a pilot valve, a pilot-controlled pressure relief valve or the sensor device of a delivery flow sensor, for example, can thereby be easily fastened to the end plate.
In one embodiment of the invention, in which the actuation device of the control spool valve is an electrical actuator device, in particular in the form of a stepper motor, there are particular advantages if the fastening device for the electrical actuator device is fastened to one end plate and the connection device for the delivery line that is in communication with the delivery connection, the connection device for the reservoir line that is in communication with the reservoir connection and the connection device for the hydraulic line that is in communication with the hydraulic connection are located on the opposite end plate. As a result of the arrangement of the electrical components and of the hydraulic components on opposite end plates, there is a clear spatial separation between the hydraulic and electrical lines that are connected to the control valve device.
If the additional component is an electrical component, in particular in the form of an electrical delivery flow sensor or an electrically actuated pressure relief valve, it is appropriate if the fastening devices are provided on the end plate that is provided with the fastening device of the actuator device of the control valve.
In one embodiment, the housing forms a control block for a first control spool valve and at least one additional control spool valve. As a result of the housing in the form of a laminated valve with a multi-layer construction, and the configuration of the end plates of the invention, the control block is small, easy and economical to manufacture.
On one end plate there may be a connection flange for the connection of a control valve to control an additional user, whereby the connection flange has one recess that is in communication with the pump channel and one recess that is in communication with the reservoir channel. In the vicinity of the connection flange there is at least one fastening device, which is a threaded boring, in the end plate. With a connection flange of this type on the control block, it is a simple matter to fasten a control valve by the fastening device for the actuation of an additional user. If an additional control valve is not provided, the recesses of the connection flange can be easily closed with a screw plug which is fastened in the fastening device.
There are advantages when a control valve device of the invention is used in a work machine, in particular an industrial truck, to actuate the hydraulic work system. The control valve device can be a control block with two control valves to actuate a lifting cylinder and a tilting cylinder of an industrial truck. As a result of the ability to connect an additional user to the connection flange, it is also possible to connect a control valve to actuate a lateral load-pushing device or a rotational unit of an industrial truck with little effort on the control block. As a result of the construction of the control block of the invention, the control block is cheaper and easier to manufacture and takes up less space in the industrial truck.